This invention relates to an extendable lock, more particularly, to an extendable lock for a steering wheel. The locking rod of the extendable lock can be easily pulled out without the utilization of a key.
Referring to FIG. 1, the conventional lock for a steering wheel comprises a locking body, a steel bail 10, biased by a spring 11, and a stopping block 12. A lock housing 13 is disposed on the upper portion of the lock body 1. A cylinder 14 is received and retained within the lock housing 13. A post 140 which has a cutout 141 at one side and a circular surface 142 at the other side is disposed on the under portion of the cylinder 14. A channel 15 is provided through the lock body 1. Handle tube 16 is attached to the rear end of the lock body 1 such that the channel 15 continues through the handle tube 16, A hook 160 is disposed at the lower portion of the handle tube 16. A locking rod 17 having a plurality of ratchet slots 171 on the rod body 17 is received by the channel 15 of the locking body 1. A second hook 170 is disposed at one end of the locking rod 17.
When the locking rod 17 is inserted into the channel 15, one of the ratchet slots 171 engages the circular portion 142 of the post 140, as shown in FIG. 2. Whether the locking rod 17 is moved in or out, the cylinder 14 is rotated by a key to release the ratchet slot 171 from the circular surface 142, allowing the locking rod 17 to be moved freely in or out. When the locking rod 17 is moved to the desired position, the cylinder 14 is rotated again to retain the ratchet slot 171 with the circular surface 142.
But, the conventional steering wheel lock has the following shortcomings:
1. It is not easy to use: Whether the locking rod 17 is moved in or out, the ratchet slot 171 must be first released from the blocking circular surface 142 by the rotation of the cylinder 14. PA1 2. The anti-theft protection is poor: If a circular steel plate is inserted into the channel 15 of the lock body 1 to press the steel ball 10 out of the channel 15, the locking rod 17 can be easily moved. On the other hand, the post 140 can be forced to rotate to release the ratchet slot 171 from the engagement of the circular surface 142. Again, the locking rod 17 can be easily pulled out. PA1 3. Since the locking rod 17 is rotatable within the channel 15, it is difficult to reach a suitable locking position of the locking rod 17.